This invention relates to a process for producing ethanol from methanol, carbon monoxide and hydrogen.
It is known in Japanese Patent Publication (Kokai) No. 149213/1976 that ethanol was produced by reacting methanol, carbon monoxide and hydrogen in the presence of a cobalt-halide-tertiary phosphine catalyst. It was also known in British Pat. No. 2,036,739 that ethanol was produced by reacting methanol, carbon monoxide and hydrogen in the presence of a catalyst comprising cobalt, other metal belonging to Group VIII of the Periodic Table, iodine or bromine and a tertiary phosphine. According to this prior methods, many by-products, such as dimethyl ether, methyl ethyl ether, acetaldehyde, dimethoxy ethane, acetic acid, methyl acetate, ethyl acetate, methyl formate and compounds having C.sub.3 or more were produced together with ethanol. That is, selectivity to neat ethanol was insufficient in the prior methods. In addition, complicated operation was necessary in the prior methods for separating ethanol from the reaction mixture.